Executive SummaryThis
report for the second quarter, 2001, consists of results from the
Environmental Surveillance, Education, and Research (ESER) Program’s
monitoring of the Department of Energy’s Idaho National Engineering
and Environmental Laboratory’s (INEEL) offsite environment.
All sample types (media) and the sampling schedule followed
during 2001 are listed in Appendix A.
This report contains results for the following:
Air Sampling During two weeks, those
ending April 11, and May 23, the average gross beta concentration for
INEEL locations was significantly higher than at Distant locations.
Also during two weeks, those ending April 18 and May 23, the
average gross beta concentration for INEEL locations was significantly
higher than at Boundary locations.
During one week (April 11), the average gross beta concentration
was higher at Boundary locations than at Distant locations.
Monthly average gross alpha and beta concentrations in air at
each sampling location are shown in Figures 10 – 15.
No 131I was detected in any of the weekly charcoal
cartridges during the second quarter. Weekly 131I
results for each location are listed in Table C-2 of Appendix C. Weekly filters for the
second quarter of 2001 were composited by location.
Selected locations were analyzed for the gamma emitting radionuclides, 90Sr, 238Pu, 239/240Pu,
and 241Am. No 238Pu
or 137Cs were detected on any of the composite samples.
Of the nine samples submitted for analysis, 241Am was
detected in five of them. Four
of the five samples had levels greater than their respective 2s and
minimum detectable concentrations (MDC) (see Table
2).
One sample, from the Arco QA-1 station, had an 241Am
result greater than 2s, but less than the MDC.
239/240Pu was detected in four of the samples
submitted. Three
of the four samples had levels greater than their respective 2s and MDCs
(see Table 2). One sample,
from the Main Gate location, had a result greater than 2s, but less than
the MDC. 90Sr was detected in two of the samples submitted
at a level greater than their associated 2s values, but less than the
MDCs, indicating they are most likely false positives. Concentrations were within the range of values measured
throughout the World. In
addition, detected values in composite samples for 241Am
ranged from 5,100 to over 10,500 times smaller than the derived
concentration guide (DCG) value. Values
detected in composite samples for 239/240Pu ranged from 5,800
to over 17,500 times smaller than the DCG value.
Details of both weekly and quarterly analyses can be found in
section 3.1. Nine atmospheric
moisture samples were obtained during the second quarter of 2001 - three
from Rexburg CMS, three from Blackfoot CMS, two from Atomic City and one
from Idaho Falls. Five
samples were greater than their associated 2s uncertainty and MDC (Table
3). For comparison, the
results measured at these locations during the second quarter of 2001
were between 87,000 and 225,000 times
lower than the DCG value for tritium in air (as atmospheric moisture) of
1 x 10-7 µCi/mL (3.7 x 10-3 Bq/mL) (see
Table B-1). Tritium
results for all atmospheric moisture samples are listed in Table C-4
(Appendix C). PM10
concentrations for the second quarter of 2001 were well below all air
quality standard levels. The
maximum 24-hour concentration was 44.9 µg/m3 on April 18, at
Rexburg CMS. Results for
all PM10 samples are listed in Table
C-5, Appendix C.
For the second quarter
of 2001, there was enough precipitation for a total of six samples –
two monthly composites from Idaho Falls, two monthly composites from the
Central Facilities Area (CFA), and two weekly samples from the
Experimental Field Station (EFS). Of
the precipitation samples collected, two EFS samples (collected on April
4 and April 18) yielded tritium results greater than the
2s
uncertainty. The sample
collected on April 4 did not exceed the MDC, while the sample collected
on April 18 did exceed the MDC (see MDC
values).
Tritium was also detected above the 2s level in the Idaho Falls
sample in May and the duplicate sample from Idaho Falls in June.
However, neither of these samples exceeded their associated MDC,
indicating false positives. While there are no specific limits on the amount of tritium in
precipitation, as a comparison the Safe
Drinking Water Act (SDWA) limits tritium in drinking water to 2 x 104
pCi/L (Appendix B-1). The
level of tritium detected in the sample from EFS that was above its
associated 2s and MDC value was 140 times lower than the SDWA limit. Water Sampling Fourteen drinking water samples were collected from selected taps
throughout southeast Idaho (Figure 16).
Samples were analyzed for gross alpha, gross beta, and tritium (3H).
Only the water samples from Fort Hall and Moreland were above 2s
and above the MDC for tritium. All drinking water samples had gross beta results above 2s,
and all but four (those from Carey, Arco, Howe and Idaho Falls) were
greater than their associated MDCs.
Of the samples analyzed for gross alpha, four, those from
Minidoka, Arco, Atomic City, and Monteview, were greater than 2s and
their associated MDCs. The
level of tritium detected in the samples from Fort Hall and Moreland
that were above 2s and the MDC were 155 to 179 times lower than the SDWA
limit. The measured levels
were also within the range of background tritium that exists throughout
the world. The level of
gross beta detected in the samples that were above 2s and the MDC were
between 4 to 18 times lower than the SDWA limit.
The level of gross beta detected in the samples that were above 2s and
the MDC were between 7 to 20 times lower than the SDWA limit.
Levels of gross alpha and gross beta observed are not
unusual given the basaltic terrain (USGS 1991).
All values are similar to those recorded in previous years, and
are well below the levels outlined for drinking water.
Five surface water samples and one duplicate sample were
collected from locations throughout southeast Idaho and analyzed for
tritium, gross alpha, and gross beta.
Results for tritium analyses showed that only one sample (Idaho
Falls) was above its 2s and MDC. At
the reported level, the tritium result is 83 times smaller than the SDWA
limit, and 333 times smaller than the DCG value.
Analytical results for gross alpha showed that the samples from
Bliss and Buhl exceeded their 2s and MDC values (Table
6).
At reported levels, the gross alpha values are between 13.6 and
16.5 times lower than the SDWA limit and between 27.3 to 33.0 times
lower than the DCG value. Results
for gross beta for all five surface water samples, and the duplicate
from Buhl, were greater than their associated 2s and MDC values (Table
6). The gross beta values
are between 7.7 and 16.8 times lower than the SDWA levels, and between
15.4 to 33.6 times lower than DCG values. Food
Sampling Milk samples were
collected weekly in Idaho Falls and monthly at nine other locations
around the INEEL (Figure
17), and analyzed for gamma emitting
radionuclides. No samples
had a 137Cs concentration greater than the 2s uncertainty.
One sample from Rupert (dated April 3) had an 131I
result greater than the 2s and MDC, however, an immediate recount showed
the sample did not exceed either the 2s or MDC, thus indicating a false
positive. Of the six
samples submitted for 90Sr analysis, all of them had
concentrations of 90Sr greater than the 2s level, and three
were above their associated MDC (Carey, Rupert, Blackfoot).
Of the four samples submitted for tritium analysis only one had a
concentration greater than its associated 2s (Roberts).
While
there are no specific regulatory limits for 90Sr in milk, as
a comparison, the DCG for 90Sr of 1.0 x 10-6 µCi/ml
in water can be used. Samples that exceeded both the 2s and MDC were from 1,209 to
1,330 times smaller than the DCG value.
Further information on second quarter milk samples can be found
in section 5.1. Individual sheep from three separate flocks were sampled
including a control flock in Dubois from the Experimental Sheep Station,
a flock from a southern INEEL allotment, and a flock from a northern
INEEL allotment. Two sheep
were taken from each flock. Thyroid,
muscle, and liver tissue were collected and analyzed for gamma emitting
radionuclides. No 131I
was found in any of the samples. Analysis
for 137Cs showed results greater than 2s in three samples
from two separate sheep: one
muscle and one liver sample collected from the same lamb on the Northern
allotment on May 18, and one muscle sample collected May 9, from a lamb
on the Southern allotment. All
concentrations of 137Cs were similar to those found in both
onsite and offsite sheep samples during recent years. Environmental Dosimeters Environmental dosimeter
locations are divided into Boundary and Distant groupings.
Boundary exposure rates ranged from 0.33 to 0.37 mR/day.
The overall average was 0.35 mR/day.
The Distant set ranged from 0.32 to 0.41 mR/day.
The average Distant value was 0.36 mR/day.
No statistical difference existed between Boundary and Distant
locations. Furthermore, all values are in line with past readings.
Table 5 lists the range and average for both groups. Summary All concentrations of
radioactivity found in samples collected by the ESER program during the
second quarter, 2001 were consistent with concentrations that have been
found in samples taken during recent years.
The ESER program could not directly attribute measured
concentrations to operations at the INEEL.
Radionuclide concentrations in all of the samples collected and
analyzed were below guidelines set by both the DOE and the Environmental
Protection Agency (EPA) for protection of human health. |
The average